Pilonidal Cyst

John P. Cunha, DO, FACOEP

John P. Cunha, DO, is a U.S. board-certified Emergency Medicine Physician. Dr. Cunha's educational background includes a BS in Biology from Rutgers, the State University of New Jersey, and a DO from the Kansas City University of Medicine and Biosciences in Kansas City, MO. He completed residency training in Emergency Medicine at Newark Beth Israel Medical Center in Newark, New Jersey.

Jerry R. Balentine, DO, FACEP

Dr. Balentine received his undergraduate degree from McDaniel College in Westminster, Maryland. He attended medical school at the Philadelphia College of Osteopathic Medicine graduating in1983. He completed his internship at St. Joseph's Hospital in Philadelphia and his Emergency Medicine residency at Lincoln Medical and Mental Health Center in the Bronx, where he served as chief resident.

The prognosis for a pilonidal cyst is generally good. Recurrences are common.

What is a pilonidal cyst?

A pilonidal cyst is a fluid-filled sac that occurs in the area at the top of the crease of the buttocks overlying the tailbone (sacrum). This cyst and the overlying skin in the area can become infected, forming a painful abscess.

Picture of a pilonidal cyst

What causes a pilonidal cyst?

It is not clear why pilonidal cysts form. At one time, it was thought pilonidal cysts might be congenital (a person is born with them) arising from embryologic cells that were in the wrong place early in development or due to repeat trauma (jeep driver's disease). It is now thought that small groups of hairs and debris (dead skin cells and bacteria) get trapped in the pores of the skin in the upper cleft of the buttock and form a "sinus," or pocket, that grows to become an abscess. This abscess forms under the skin (subcutaneously) and can result in scar tissue that can become infected repeatedly.